|
|
BABAR Collaboration(Lees, J. P. et al), Martinez-Vidal, F., & Oyanguren, A. (2016). Tests of CPT symmetry in B-0-(B)over-bar(0) mixing and in B-0 -> c(c)over-barK(0) decays. Phys. Rev. D, 94(1), 011101–7pp.
Abstract: Using the eight time dependences e(-Gamma t)(1+C(i)cos Delta mt+S(i)sin Delta mt) for the decays Upsilon (4S) -> B-0(B) over bar (0) -> f(j)f(k), with the decay into a flavor-specific state f(j) = l(+/-)X before or after the decay into a CP eigenstate f(k) = c (c) over barK(S,L), as measured by the BABAR experiment, we determine the three CPT-sensitive parameters Re(z) and Im(z) in B-0-(B) over bar (0) mixing and vertical bar(A) over bar /A vertical bar in B-0 -> c (c) over barK(0) decays. We find Im(z) = 0.010 +/- 0.030 +/- 0.013, Re(z) = -0.065 +/- 0.028 +/- 0.014, and vertical bar(A) over bar /A vertical bar = 0.999 +/- 0.023 +/- 0.017, in agreement with CPT symmetry.
|
|
|
|
Wilkinson, C. et al, & Stamoulis, P. (2016). Testing charged current quasi-elastic and multinucleon interaction models in the NEUT neutrino interaction generator with published datasets from the MiniBooNE and MINERvA experiments. Phys. Rev. D, 93(7), 072010–19pp.
Abstract: There has been a great deal of theoretical work on sophisticated charged current quasi-elastic (CCQE) neutrino interaction models in recent years, prompted by a number of experimental results that measured unexpectedly large CCQE cross sections on nuclear targets. As the dominant interaction mode at T2K energies, and the signal process in oscillation analyses, it is important for the T2K experiment to include realistic CCQE cross section uncertainties in T2K analyses. To this end, T2K's Neutrino Interaction Working Group has implemented a number of recent models in NEUT, T2K's primary neutrino interaction event generator. In this paper, we give an overview of the models implemented and present fits to published nu(mu) and (nu) over bar (mu) CCQE cross section measurements from the MiniBooNE and MINER nu A experiments. The results of the fits are used to select a default cross section model for future T2K analyses and to constrain the cross section uncertainties of the model. We find strong tension between datasets for all models investigated. Among the evaluated models, the combination of a modified relativistic Fermi gas with multinucleon CCQE-like interactions gives the most consistent description of the available data.
|
|
|
|
Hernandez, P., Kekic, M., Lopez-Pavon, J., Racker, J., & Salvado, J. (2016). Testable baryogenesis is in seesaw models. J. High Energy Phys., 08(8), 157–29pp.
Abstract: We revisit the production of baryon asymmetries in the minimal type I seesaw model with heavy Majorana singlets in the GeV range. In particular we include “washout” effects from scattering processes with gauge bosons, Higgs decays and inverse decays, besides the dominant top scatterings. We show that in the minimal model with two singlets, and for an inverted light neutrino ordering, future measurements from SHiP and neutrinoless double beta decay could in principle provide sufficient information to predict the matter-antimatter asymmetry in the universe. We also show that SHiP measurements could provide very valuable information on the PMNS CP phases.
|
|
|
|
ATLAS Collaboration(Aad, G. et al), Alvarez Piqueras, D., Barranco Navarro, L., Cabrera Urban, S., Castillo Gimenez, V., Cerda Alberich, L., et al. (2016). Test of CP invariance in vector-boson fusion production of the Higgs boson using the Optimal Observable method in the ditau decay channel with the ATLAS detector. Eur. Phys. J. C, 76(12), 658–25pp.
Abstract: A test of CP invariance in Higgs boson production via vector-boson fusion using the method of the Optimal Observable is presented. The analysis exploits the decay mode of the Higgs boson into a pair of t leptons and is based on 20.3 fb(-1) of proton-proton collision data at root s = 8 TeV collected by the ATLAS experiment at the LHC. Contributions from CP-violating interactions between the Higgs boson and electroweak gauge bosons are described in an effective field theory framework, in which the strength of CP violation is governed by a single parameter (d) over tilde. The mean values and distributions of CP-odd observables agree with the expectation in the Standard Model and show no sign of CP violation. The CP-mixing parameter (d) over tilde is constrained to the interval (-0.11, 0.05) at 68% confidence level, consistent with the Standard Model expectation of (d) over tilde = 0.
|
|
|
|
Granero, D., Candela-Juan, C., Vijande, J., Ballester, F., Perez-Calatayud, J., Jacob, D., et al. (2016). Technical Note: Dosimetry of Leipzig and Valencia applicators without the plastic cap. Med. Phys., 43(5), 2087–4pp.
Abstract: Purpose: High dose rate (HDR) brachytherapy for treatment of small skin lesions using the Leipzig and Valencia applicators is a widely used technique. These applicators are equipped with an attachable plastic cap to be placed during fraction delivery to ensure electronic equilibrium and to prevent secondary electrons from reaching the skin surface. The purpose of this study is to report on the dosimetric impact of the cap being absent during HDR fraction delivery, which has not been explored previously in the literature. Methods: GEANT4 Monte Carlo simulations (version 10.0) have been performed for the Leipzig and Valencia applicators with and without the plastic cap. In order to validate the Monte Carlo simulations, experimental measurements using radiochromic films have been done. Results: Dose absorbed within 1 mm of the skin surface increases by a factor of 1500% for the Leipzig applicators and of 180% for the Valencia applicators. Deeper than 1 mm, the overdosage flattens up to a 10% increase. Conclusions: Differences of treating with or without the plastic cap are significant. Users must check always that the plastic cap is in place before any treatment in order to avoid overdosage of the skin. Prior to skin HDR fraction delivery, the timeout checklist should include verification of the cap placement. (C) 2016 American Association of Physicists in Medicine.
|
|
